Refrigeration apparatus



March 9, 1954 w BAUER 2,671,603

REFRIGERATION APPARATUS Filed April 14. 1949 s Sheets-Sheet 1 IN VEN TOR.

William E. Bauer W%%ML any March 9, 1954 w BAUER 2,671,603

REFRIGERATION APPARATUS Filed April 14, 1949 5 Sheets-Sheet 2 Cooliry 001' Z Receiver IN VEN TOR.

William E. Bquer W%%% aiz' fxpansion Coils March 9, 1954 w. E. BAUER 2,671,603

REFRIGERATION APPARATUS Filed April 14, 1949 5 Sheets-Sheet 3 IN VEN TOR.

7 William E. Bauerwa ag Mar h 9, 1954 w. E. BAUER 2,671,603

REFRIGERATION APPARATUS Filed April 14, 1949 5 Sheets-Sheet 4 I34 INVENTOR. 138- I Wlllzam 56116! BY c A [w 66 m2 MQW/ -M dz'y March 9, 1954 w UE REFRIGERATION APPARATUS Filed April 14. 1949 5 Sheets-Sheet 5 IN V EN TOR. William Bauer "QZZW J 7% zfl Patented Mar. 9, 1954 UNITED STATES PATENT OFFICE.

REFRIGERATION APPARATUS Williamv E. Bauer, Chicago, Ill.

ApplicationApril 14, 1949, Serial- No. 87,493

4. Claims.

This invention relates to refrigeration.v appa-- ratus and is disclosed in such adaptation, although it is understood, and may be readily understood by those skilled in the art, that oer tain parts of the apparatus are susceptible to a broader range of uses.

One of'the object's-of my invention is to provide compact efllcient refrigeration apparatus adapted. to mounting on a single removable wall of a refrigerator cabinet, so that the apparatus is readily removable as a complete unit for service or replacement and may be replaced by another unit during aservice operation.

It is-another obziect'ot this invention to provide a unitary, electrically driven, mechanical oompressorunit. for use in apparatus of: the type re ferred. to and wherein. the electrical drive parts and; mechanical compressor parts are separated.

As. another object, it is within the comprehension of my invention: to provide a compressor or pump unit adapted to uses including the com-- pression' of refrigerating: gasses and wherein the number and. production. cost of parts are both materially restricted.

This invention further has within. itspurvi'ew of refrigeration apparatus embodying a come pressorr unit wherein the: construction. and; arrangement are such that l'ap sealed; joints and the necessity of extreme precision; in machining are avoided without e'fi'ecting. leaks: or lossof; efficiency.

I have additionally provided, in this invention, a mechanical: compressor having relatively few parts; which parts are of relatively simple con.- struction and readily assembled.

For effecting: the foregoing advantages in my disclosed. compressor unit, as well as to' provide a unit adapted to uses requiring the: production of: pressures above or below normal atmospheric pressures. I. have utilized" a structure embodying arotary cylinder: block having therein a. plurality of axially displaced sets oi" radially disposed cylinder bores, with pistons-in the setsofi bores? opposed i i phase for balanced operation; valve action being.accomplished:byrelative movement between the rotary cylinder block: and a grooved closure member.

Other objects and advantages of the invention will be apparent from the following descrip tion and. the accompanying. drawings which. similar characters of. reference indicate similar parts throughout the several views.

hinge l-S.

; portion of the apparatus illustrated in Figs. 1 and 2, drawnto a larger scale than Figs. 1 2

and: having parts cut-away to show details of construction Fig. 4. is a. top plan. view of the refrigeration apparatus illustrated. in Fig. 3;

Fi 5 is" a fragmentary side elevational view of a portion of. the apparatus depicted in Fig. 3 and. drawn to a somewhat larger scale than Fig; 3-;

Fig. 6 is a fragmentary side sectional view taken substantially on. a line 5'-6- of Fig. 5 and in the direction indicated by accompanying arrows;

Fig. 7 is a fragmentary sectional view corresponding to a portion of the structure shown in Fig. 6' but drawn to a larger scale;

Figs. 8' and 9 are respectively top sectional" views taken substantially on lines 8-32 and El-9' oii Fig. 7 and illustrating corresponding positions of th'e'parts occurring. at one" step of theoperation of the apparatus, and

Fig. 10 is an exploded. view indicating the structure and arrangement of certain internal parts of. the apparatus;

Having reference to the exemplary embodiment of my invention which is disclosed in the accompanying drawings for illustrative purposes, it is my preference to provide refrigeration apparatus including a compact mechanical coohn'g unit adapted to be entirely supported with referenceto one removable wall section of a; refrigerator cabinet; as depicted in Figs. 1 and 2. To this end, I have providedarefrigerator cabinet l5 including a box portion it which opens at the top; a removable wall section H of a size to cover a portion of the open box top and a movablecoverl-il of a size normally to cover the remainder of the open box top and movably connected to the removable wall section by a As is usual in the structure of rei'rigerator cabinets, the walls of the box portion it, as well as the removable wall section IT and movable. cover L8,. are of suitable heat insulating construction such, for example, as including a filler of heat insulating material it. as shown in Fig. 3.

In the normal assembled relationship of the parts of the refrigerator cabinet, as depicted in Fig. l, the removable wall section ii is desirably secured in place by removable fastening means (not shown), such as screws or the like. As shown in Fig. 2, the hinge is preferably comprises a hinge plate 22 secured to the removable'wall section H at one edge thereof, a hinge plate 23 secured to the cover and a removable hinge rod 25 by which the hinge plates are normally connected for relative swinging movement.

In order to provide for the removal and/or replacement of the mechanical refrigerating equipment with the removable wall section 17, a part of that equipment is mounted within a housing on the ex erior surface of the wall section ll, while an evaporator 26 is carried internally of the wall section, suitable connections for the flow of refrigerant to and. from the evaporator being made by pipes 2i and 26 (Fig. 3) extending through the wall section i'l. Within the housing is mounted a motor driven compressor unit 29 and a condenser coil 35 carried by a frame 32, which frame is secured to the wall section II. Also within the housing 25 and connected in the refrigeration system in the usual manner are a receiver 33, a drier 34 and a pressure switch 35. In the refrigeration equipment disclosed, the motor driven compressor unit 29 includes a driving motor 35 and a compressor 37. Also in the disclosed equipment, and as shown in Fig. 3, the low pressure side of the evaporator is connected to the inlet side of the compressor through the pipe 28 and a pipe 38. The pressure switch 35 is connected to the pipe 28 and is operated by the pressure of the refrigerant therein to control the cycles of operation of th compressor unit. 0n the discharge side of the compressor, a pipe 39 and a pipe ti} conduct the compressed refrigerant to the condenser 35 in which it is cooled and from whence it flows into the receiver 33, through the drier 34 and through the pipe 21 to an expansion valve 42 and through the latter valve to the evaporator.

As an element contributing materially to the compactness and unitary nature of the disclosed structure, I have provided the motor driven compressor unit 29 which, in addition to being compact and housed in a unitary closure, has many unique features which will be discussed as the description progresses. As has been mentioned in the more general portion of the description, it is understood that while being termed a compressor in its association with the disclosed refrigeration apparatus, this term is used in a broad sense because the disclosed compressor structure is well adapted to use in other pumping operations such, for example, as a vacuum pump.

Referring more in detail to the structure of my motor driven compressor unit 29, as illustrated in Figs. 3 to 10 inclusive, a unitary housing 43 has cylindrical side wall portions 44 and 45 extending in opposed directions from an integrally formed and radial partition wall 46; the opposite ends of the cylindrical side wall portions opening outwardly away from the partition. The cylindrical side wall portion 2-4 and the radial partition 46 define a motor housing compartment 4?. Centrally of the partition 46 and coaxial with the cylindrical side wall 44 an integrally formed boss 48 projects into the motor housing compartment from the partition 46 and has therein a bearing bore 49. The bearing bore 49 extends between the motor housing com- 4 partment .1 and a compressor housing compartment 5!) within the cylindrical side wall portion G5, and is in concentric and coaxial relationship to the interior cylindrical surfaces of those compartments.

Inside of the compressor housing compartment 5!], a cylinder block 52 has an external cylindrical surface 53 which fits into and has a running fit for rotational movement relative to the cylindrical internal surface of the cylindrical side wall portion 45. In my preferred construction, the cylinder block 52 is in the form of a generally cylindrical and hollow shell having a web 54 providing a closure at one end, and the hollow interior being open at the other end. Also, a shaft 55 is drivingly secured to the web and projects therefrom in coaxial relationship to the cylindrical cylinder block surface 53. A bearing portion 5% on the shaft 55 fits the bearing bore 49, while an extending end portion 53 of that shaft is drivingly connected to a motor rotor 58.

Although any desired type of motor rotor may be used to meet predetermined conditions of operation, my disclosed embodiment of the invention depicts the use of a squirrel cage rotor of relatively conventional form. Secured within the cylindrical internal surface of the side wall portion M of th housing is a stator 59 in driving relationship to the rotor 58. Being disposed for vertical operation, in the present instance, a collar 55! provides a thrust bearing and spacer between the end of the rotor 58 and the end of the bearing boss 48. By preference, the open end of the motor housing compartment 41 is closed and sealed hermetically by a cover 62 secured to the end of th cylindrical side wall portion 44 by removable fastening means, such as screws 63.

On the outer end of the web 54 of the cylinder block, a plane circular bearing surface 64 adjacent the shaft 55 provides one end bearing for the cylinder block in opposed relationship to the thrust bearing provided by the collar 66. At the oppos te end of the cylinder block, and adjacent the cylindrical wall portion 53, another plan end surface 65 serves as a second end bearing surface for the rotar cylinder block. A second cover plate 65 secured to the open end of the cylindrical side wall portion 35 closes and hermetically seals the compressor housing compartment 50 and presents a plane inner surface p t ng running engagement with the end surface 65 of the cylinder block Removable fastening means, such a screws 61, are utilized to hold the cover 66 in plac relative to the cylinder wall portion 45.

From the description thus far presented, it may be understood that the driving power of the motor, which includes the rotor 58 and the stator 59, effects rotational movement of the cylinder block 52 within the compressor housing compartment 58. Thus, the cylinder block, in the present instance, is a moving part of the compressor. While various numbers and arrangements of cylinders and pistons may be utilized for accomplishing the desired pumping action as a result of the cylinder block rotation, it is my preference to illustrate a system. which provides relatively balanced, multi-cylinder operation.

As shown in Figs. 5, 7, 8 and 9, the cylinder block 52 includes two sets of radial cylinder bores (Figs. 8 and 9) separated axially of the cylinder block. In the present instance, each set includes six cylinder bores equally spaced circumferentially of the cylinder block, with the cylinder horas; oi: the; two! sets; aligned,- axialhr of the. riinner-block; Qmr sets. as; dcni tert. n F g; 8-, incluces; csiinder ores Bit. tit. :01.. :2; a and; The; ethos set as: shorininaliisa. 9; comprises; y1-

inden bores; 116;, 1-,1r, 18:... 19; and- Bils Each of the; cy inden bores; extends through; the cylindricalside; wall: of? the, ealiniicn block. in-

direction radialto thorotational; oi the-cylinder bloch.

Pistons 82, 8'3, .14;. 5;. at and. 8:1: are mounted for reciprocating mov ment: h cy n bo 6.8;. 6. 1Il',. 2.-., 113; and: 1&4: resnectivelyr while the cylinder: bores" 15; 16, 11 18;, 14}, and 80- havepistons 88:, as. 911;, 9.2,, 93 amt 94 respectively, mocha d: ior reciprocatin ovement. therein. Pref,- erahlm, each of. the pistons; is provided with. a piston; ring: t5. extending; c ncumferentially there.- of. in: a groove: at near: outer. cndoi. the iston.

As shown in- Eig s; (it Lo inclusive, the several pistons; are: of. like. construct on; so; ha a d scription of one will sufiice for the others. Each soon piston; in: the; present instance, com-prises a solid; m tal? cylindan, the outer cnct, oi wh ch; is preterably' cnrveol: to; contorm too the.- cylindrical outer surface f. the: cylind r l k wh n the piston; is in: its; normal.- nositionv in, one oi the cylinder bores... At the inner each piston has an arcuate bearing; slot, in, theaxis, of, the arouate surface of which passes through and is perhendicnlar: to; the longitudinalaxis of. the

piston. Also, the; ancuate bearing slot has an arcuate-extent greater than, 180 degrees, but less than 360; degrees, with: the axis of, thearc' positioned: so; that. the.- slot opens. outwardly at the innenencl of the pistons part.- oi-. he: additional. structure: utilized in the' disclosed, ensemble. for effecting reciprocation of, the; pistons in; sequential order in the sets thereof and witltthc movements of, the sets of pistons dephasecl for fierce. balancing purposes, I. utilize astaticnary; crank. shaft. 9.8 which, in: the Presentinstance; is ncn-notatably securedtoand supported from, the cover plate 65. by a shaft extension 9.3. extending through a. bore 1-00, in the; coverplate. and secured; in. place. byfa ening; means; such as: a nut. In the, disclosed structure, thecrankshaft 9.8 has a circ lar rank anm nortion Instr-om which, crank pins [34 and [f croi ct in opposite directions; said crank, ins bein disgcsed with their; axes, spaced: apart. The? shaft. extension 99. is coaxial with. the. crank pins. L andihe-hore I;:0.fl in the coverplate 6.6- is snaced; to, one sidaof. the axisof shaitbearing 5.6, so that when: proper y p tion d, as. shown in Fig. 7; acenten linohetweenthe axes of. the. crank p ns o nc des with th ax s of shaf 55. hus, the; w n-1;; p n 104. and. I415.- e norm ly disposed! p dct tmincd positions n. opp te s idfisfl tf ihfi'axififli. rotation-o the cylinder. l c A-lsc, nsthc' a s mbl-x, a h of. thecizank pins. I214 and: "ii o h cram; haft is, aligned axiallyof he ylin er lock. with one. of. the..- sets of, cylinden ho as.

Bearing collars IIlIi and; I01 are of. similar constru tion-., amt each has. a cen ral. heating; bore i 11 xtending. therethrouehi and. rotatable. on. one of. hccxankpinsot th crankshaft... inte ral y form d n the he r ng collar. and; p oie tins. in a irection: radial o he. xis i the. central. hear nsgbore I118.- is aisine ec nn ting rod. Hi9.- t the. end. remo from; tho b aring. co11ar, the. connett n rod, L09. has an. arcua a nd; b ar ng. pottion. no. intcsna ix tormcdtheneon, with. th ax s Qi. thcaili li ta suitface. thereof, substantially natal cl. o: the; of. he. en ral. icorice. bore.

1118,. at uata bearing nortion tin. into,

thcaitcuate hearingrslot' 91 011' one. ot the pistons; the arcuate extent of the bearing portion andzthe thickness: at this. connecting; rod: being: proportioned to the, arcuate. extent; and: bearing: slot opening in. the piston; that the. connecting rod and piston areadantefi to limited relatiyeswinge ins; movements. At equallyspaceck positions circumiercntially of the: hearing.- collar from the longitudinal; centen line; of; the; connecting rod [119a,aiicuatehearinsslots Hit, H 3},v I I4; [1.5 and L16 extend through the peripheral. margin of the: hearing: collar with: theaxes of: their arcuate surfaces in substantially parallel relationship: to the: axes; of: the. central; bearing; bore N18. The diameters; arcnato. extents and: positions of. the arcuatahearing. slots; nadially of the; bearing collar are such that those slots open outwardly of the collalrini a. direction radial; thereto.- and each; has an arcuate. extent of: more than 18.0. de rees; but less than. 360 degrees;

Ilhe connectin rod: 1119i of: the. bearing collar I B1 connects the. piston; 34; to the bearing collar andthence to; thocrank: pin r05, while.- connecting rods I.I:1I, litii, Iii-9;, 12:0 and. 12.2; respec.- tively provide movableoperating connections between the bearing collar Idlfl: and. their pistons 88, 89; 9.01,. 92. and. 33.. of: the. same set. In, the othenset; the connecting: rod; I09. on the: bear n collar 16' is connected: to: the piston. 8 while pistons 85,. 86.31, 8 2; and; as are. respectively'corrnected; to. the bearing collar: through; connecting rods I13; IKZA, I25, I25: and. 32115.. By; prcferencfiz the. connecting. rods: I-|:.1;,. l I;8; H19; 120; i221 1:23;, I24, I 25, I26 and I21 are similar in size andzstructore. Each. hasam ancuate; end bearing; portion t-ZB; adaptedtofit into the bearing slot 91: of: one of the-pistons. Also, each has at its: opposite end an arcuate bearing portion I529. having an axis parallel to; that. end; heating. portion, [28; and of: a size to fit. into: one. of the arcuate hearing slots: in one cit-the: hearing col-lars. Preferably, the; length of each hearing portion. [-28- conforms: substantially to. the diameter of the piston which; it: ad:- joinsand; the; opposite end sniifaces thereof coniormtn thclcultvatureof thczniston sorta-ca Also, the: length. of each. arcuate hearing portion. I29 is. substantially equal to the axial. length of; the bearing collar which it: adjoins. In. the: assemhis; as depicteok in. Fig. the hearings collars fit snu ly between opnos ch bearing faces; i301 and Ii-32: at the; crank arim portion. of the crank shaft and: bearing surfaces; I331 anoi L34; on he inner cylinder block. surface: and: inner cover.- plate. su fiace: respective y, so. that: those bearing surfa es ends; of he: c nnec ing rods in place an an direction...

In", the assembly of: the; compressor, the con.- acctina rods I523; n.4,. I; lit and 21 are; as semhlcd with heir hearing, collar Izllfi nd. their respect-me.- pistons the cylinder block; 'Ilhen the: crank pin. I04 is inserted: into the central nearing bore [08' amt the connecting rods; H1, H8, H9, I 20: and I222: are assembled with their respective pistons in the cylinder block and the bearing collari0 1, after which the crank shaft is positioned an'clsecured relative tothe cover plate 66-.

Between the-sets of'cyli-nder-bores in the cyiinr der block and circumferential'ly of the outer. surface ofthat block, a ring groove ['35 is provided which. carries an. xt nsion tyne seal ng. ring I35, Also. n ar he. opposite ends. 01 the. cylinderv block, peripheral ring. gmoves. L3! and. Hi8. are omen. which latter tins sitcoms... nny an:

pansion type sealing rings I39 and I40 respectively.

From the foregoing description, it may be readily understood that during rotary movement of the cylinder block, the pistons of each set are reoiprocated sequentially between extended and retracted positions relative to the cylinder bores. When the pistons are in a fully extended position relative to the cylinder bores, it is my preference that the outer ends thereof shall be substantially flush with the outer surface of the cylinder block. At the other ends of the piston strokes, the pistons, of course, remain in their respective cylinder bores, although retracted to provide a substantial displacement volume in respect to diameters thereof. Furthermore, the positioning of the crank pins I94 and I on opposite sides of the axis of rotation of the cylinder block displaces the phases of move ments of adjacent pistons of the two sets by 180 degrees, thereby balancing the forces on opposite sides of the cylinder block.

While it is expected that a substantial portion of the interior of the cylinder block will be filled with oil during operation of the compressor to lubricate the moving parts and to aid in providing an effective gas tight seal between the parts with only normal machining limits and fits therebetween, the sealing rings I36, I39 and I40 provide running seals between the cylinder block and housing at their opposed wearing surfaces. These factors, together with the fact that the outer housing is hermetically sealed, prevents gas leakage.

In the disclosed structure, the valve action necessary for making effective use of the piston movements is accomplished without the use of additional parts, cams and the like. In the present instance, I have provided arcuate circumferential slots M2 and. E43 facing inwardly of the housing side wall portion 45 in alignment for communication with the ends of the cylinder bores during rotation of the cylinder block, which slots, in the present instance, each extend around less than 180 degrees of the cylinder block and are placed at circumferentially spaced positions. In like manner, similar slots I44 and I45 in the inner surface of the housing side wall portion 45 are aligned for communication with the cylinder bores of the other set during rotation of the cylinder block. Assuming the direction of cylinder block rotation indicated by arrows in Figs. 8 and 9, and when the disclosed mechanism is utilized as a compressor, the slots I42 and I44 serve as discharge slots, while the slots I43 and I45 serve as intake slots. Communicating with the discharge slots I42 and I44 respectively are discharge passages I46 and I4! in the housing side wall portion 45 and on opposite sides thereof. Also, on opposite sides of the housing side wall portion 45, intake passages I48 and I49 extend through the compressor side wall portion and communicate with inlet slots I43 and I45.

As viewed in Figs. 8 and 9, the designated direction of rotation of the cylinder block is clockwise. At the end of each discharge stroke, the piston is, of course, moved to an extended position such that the end thereof is substantially flush with the outside wall of the cylinder block. As the piston progresses, it is retracted from that position. In my preferred compressor structure which is disclosed, the initial movement of retraction of the piston occurs when the cylinder bore is out of communication with both valve slots, so that a preliminary pressure reduction is eifected in the cylinder bore. As the retracting movement continues to completion, the cylinder bore is in communication with the inlet slot, so as to effect a pressure reduction, or suction in the inlet slot and its communicating passage. There is then, in my preferred construction, a substantial period during which the cylinder bore is out of communication with both slots, in order that the pressure in the cylinder bore will be built up before the discharge into the discharge slot and its communicating passage are effected by the opening of the cylinder bore into that discharge slot. With this arrangement, the intake period for each cylinder is of greater extent than the discharge period. It, however, enables the building up of a pressure in the cylinder bore which equals or exceeds that in the discharge passage before the cylinder bore is opened into the discharge slot for communication with that passage.

While I have illustrated a preferred embodiment of my invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a compressor or the like adapted to use in refrigeration apparatus, the combination comprising a housing having an internally cylindrical side wall and end walls presenting oppositely disposed plane surface portions, one of said end walls having a bearing therein coaxial with the internally cylindrical surface, a cylinder block having a cylindrical outer surface and plane end surfaces dimensioned to provide a running fit with the cylindrical surface and plane surface portions of the housing, said cylinder block also being interiorly hollow and having an integrally formed shaft projecting axially from only one end thereof which is fitted for rotation in said bearing, said cylinder block having therein axially separated sets of cylinder bores with the sets each in coplanar relationship and extending radially from the hollow interior through the cylindrical surface thereof, said cylinder block also having a peripheral groove between the outer ends of said sets of cylinder bores and a sealing ring mounted in said groove for engagement with the cylindrical surface of the housing, a stationary crank shaft having crank pins in the general planes of the sets of cylinder bores and positioned eccentrically of the axis of the cylinder block on opposite sides of said axis, sets of pistons each mounted for sliding movement in the cylinder bores of said sets, and means including a bearing collar and connecting rods for connecting the pistons of the sets to the crank pins so that rotation of the cylinder block effects reciprocation of the pistons.

2. In a compressor as defined in claim 1, said bearing collar comprisin a body portion having a central crank shaft bearing therein and having one of said connecting rods integrally formed thereon and projecting from the body portion in a direction radial to the crank shaft bearing, said body portion also having in the periphery thereof and spaced peripherally of the body portion with reference to the integral connecting rod a plurality of arcuate bearing slots opening radially of the body portion and having an armate extent of more than degrees, and others of said connecting rods having at the ends thereof integral cross pin portions fitting into the arcuate bearing slots to provide force transmitting connections permitting limited relative movements of the bearing collar and said others of the connecting rods.

3. In refrigeration apparatus, a motor driven compressor unit comprising, in combination, a housing having coaxial cylindrical wall portions extending oppositely from a radial partition wall, opposite ends of said cylindrical Wall portions being open, said radial partition wall having a bearin therein which is also coaxial with the cylindrical wall portions, a cylinder block having a cylindrical outer surface of a size to have a relatively close running fit in one of the cylin drical wall portions and having a shaft projecting axially from only one end thereof in concentric relationship to the cylindrical surface, said shaft fitting into said bearing to support the cylinder block for rotation in said one of the cylinder wall portions, a motor rotor drivingly secured to said shaft on the end thereof opposite the cylinder block and within the other cylindrical wall portion of the housing, a stator secured Within said other cylindrical wall portion in driving relationship to the rotor, an end cover sealing the end of the housing in which the rotor is mounted, a second end cover for sealing the end of the housing in which the cylinder block is mounted, said cylinder block having a hollow interior and cylinder bores extendin radially from the hollow interior through the cylindrical outer surface thereof, a stationary crank-shaft secured to the second end cover and extending into the hollow interior of the cylinder block, pistons mounted for sliding movement in the cylinder bores, connecting rods connecting the pistons to the crank shaft so that the pistons are reciprocated in the cylinder bores during rotary movement of the cylinder block, and segmental and circumferentially separated inlet and discharge channels in said one of the cylindrical wall portions in aligned relationship to the cylinder bores axially thereof and having inlet and discharge ports communicating therewith, said cylinder bores being divided into two sets separated axially of the cylinder block, the cylinder bores of each set being equal in number, equally spaced apart and in aligned relationship axially of the cylinder block to those of the other set, and said crank shaft having crank pin portions disposed to dephase the movements of adjacent pistons in the sets of cylinder bores substantially 180 degrees.

4. In a compressor or the like adapted to use in refrigeration apparatus, the combination comprising a housing having an internally cylindrical side wall and end walls presenting oppositely disposed plane surface portions, one of said end walls having a bearing therein coaxial with the internally cylindrical surface, a cylinder block having a cylindrical outer surface and plane end surfaces dimensioned to provide a running lit with the cylindrical surface and plane surface portions of the housing, said cylinder block also being interiorly hollow and having a shaft projecting axially from one end thereof which is fitted for rotation in said bearing, said cylinder block having therein axially separated sets of cylinder bores wherein the cylinder bores of each set are in coplanar relationship and extend radially from the hollow interior through the cylindrical surface thereof, a stationary crank shaft having crank pins in the general planes of the sets of cylinder bores and each positioned eccentrically of the axis of the cylinder block, sets of pistons each mounted for sliding movement in the cylinder bores of said sets, and means including a bearing collar and connecting rods for connecting the pistons 0f the sets to the crank pins so that rotation of the cylinder block effects reciprocation of the pistons, each of said pistons having a cylindrical body with an end facing inwardly of the cylinder block, the inner end of said cylindrical body having a bearin slot of arcuate section therein and extending laterally of the body axis, the arcuate extent of said bearing slot being greater than 189 degrees, and said connecting rods each having on an end thereof an integral cross pin portion of a size to fit said bearing slot, said cross pin and bearing slot providing a force transmitting connection between the connecting rod and piston and through which they are relatively movable to a limited extent.

WILLIAM E. BAUER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 493,263 Fogg Mar. 14, 1893 1,051,306 Bertrand et a1 Jan. 21, 1913 1,241,704 Borras et a1 Oct. 2, 1917 1,250,860 Guy Dec. 18, 1917 1,714,706 Wilking May 28, 1929 1,721,225 Levering July 16, 1929 1,902,345 Valentine Mar. 21, 1933 1,910,498 Ploeger May 23, 1933 1,922,091 Hull Aug. 15, 1933 1,974,961 Johnson Sept. 25, 1934 2,150 347 Sorenson Mar. 14, 1939 2,153,773 Patrignani Apr. 11, 1939 2,262,593 Thomas et al Nov. 11, 1941 2,455,162 Donnelly Nov. 30, 1948 FOREIGN PATENTS Number Country Date 468,097 Germany 1927 469,883 Great Britain 1937 875,386 France 1942 

